Effects of Pixel Density on Subjective Legibility of Liquid-Crystal Displays.

We investigated the effects of pixel density, character matrix size, and character size on the subjective legibility of liquid-crystal displays (LCDs). At a 30cm viewing distance, 50 subjects assessed the legibility under 33 different display conditions, we used 6 × 4.5 photographs to simulate the LCDs. We found that the character matrix for Japanese characters should be more than 10 × 10pixels when the characters are smaller than 2.7mm. For characters 2.7 to 3.5mm, the character matrixes should be 15 × 15 to 17 × 17 for single-stroke characters, and 22 × 21 to 27 × 27 for double-stroke characters. These results show that the preferred character matrix depends on pixel density, character size, and stroke width. The preferred stroke width for Japanese characters is 200 to 300 μ m. From the legibility point of view, the pixel density of displays should be increased to 250 or 300pixels per inch.